1. Field of the Invention
The present invention relates to a cladding material comprising dissimilar metal materials to be joined, and in particular to a cladding material comprising materials to be joined and an intermediate layer between them, and a manufacturing method therefor.
2. Description of the Related Art
Recently, aluminum or aluminum alloys have been used as the material for ships and vessels. Aluminum and aluminum alloys have excellent workability and are light weight. Therefore, a case wherein they are used together with steel, which is the main material for ships and vessels, are increasing. In order to join aluminum or the like with steel methods such as diffusion joining, friction joining, explosive joining, and the like have been used.
However, the joining strength is insufficiently in diffusion joining.
Friction joining is suitable for joining parts of relatively small size; therefore, it is unsuitable for joining parts of large size such as parts for ships and vessels.
In explosive joining, it is necessary to previously sandwich an insert material such as Ti, Ni, and the like between the materials to be joined; therefore, it has a problem in that the structure of the joining parts is complicated and is a high cost process.
In consideration of the above-described problems with conventional technology, an object of the present invention is to provide a cladding material which has a high joining strength and excellent productivity, and a manufacturing method therefor.
In order to achieve the object, the present invention provides a cladding material comprising: a first material to be joined which is made of aluminum or an aluminum alloy; a second material to be joined which is made of a single metal or an alloy and which is to be joined with the first material to be joined; and an intermediate layer which is provided between the first material to be joined and the second material to be joined.
The first material to be joined is referred to as the xe2x80x9cfirst materialxe2x80x9d, and the second material to be joined is referred to as the xe2x80x9csecond materialxe2x80x9d below.
In the cladding material, the intermediate layer is provided between the first and second materials; therefore, it is possible to realize the joining strength between the first and second materials which is larger than the tensile strength of the first material.
In addition, the present invention provides a cladding material in which a first material which is made of aluminum or an aluminum alloy and a second material which is made of a single metal or an alloy are roll joined under vacuum conditions wherein the joining temperature is in a range from 260 to 600xc2x0 C.; the draft of the first material is 14% or greater; and an intermediate layer is provided between the first and second materials.
It is preferable to carry out heat treatment at 300 to 500xc2x0 C. for 10 to 60 minutes after the roll joining.
In the cladding material, since the intermediate layer is provided between the first and second materials by roll joining under such conditions, it is possible to realize the joining strength between the first and second materials larger which is than the tensile strength of the first material.
It is preferable for the intermediate layer to mainly comprise an amorphous phase.
In the cladding material, since the intermediate layer mainly comprises an amorphous phase, it is possible to improve the joining strength between the first and second materials.
In particular, when the second material is made of Fe or an Fe alloy, an intermediate layer mainly comprising an amorphous phase can be provided.
In addition, it is preferable for the intermediate layer to comprise a mixed phase containing an amorphous phase and a crystalline phase.
In the cladding material, since the intermediate layer which comprises a mixed phase containing an amorphous phase and a crystalline phase is provided, it is possible to improve the joining strength between the first and second materials.
In particular, when the second material is made of Fe or an Fe alloy and the first and second materials are heat treated after roll joining, an intermediate layer which comprises a mixed phase containing an amorphous phase and a crystalline phase can be provided.
In addition, it is preferable for the intermediate layer to mainly comprise a crystalline phase.
It is possible for the cladding material to improve the joining strength between the first and second materials via the intermediate layer which mainly comprises a crystalline phase.
In particular, when the second material is made of Ti, Zr, or Hf, or when the second material is made of Fe or an Fe alloy and the first and second materials are heat treated after roll joining, an intermediate layer which mainly comprises a crystalline phase can be provided.
It is preferable for the intermediate layer to comprise aluminum as the main component and the single metal or the alloy which comprises the second material as the sub-components.
In the cladding material, the intermediate layer comprises aluminum which comprises the first material as the main component and an element which comprises the second material as the sub-components. That is, the intermediate layer comprises all the elements comprising the first and second materials. Therefore, the joining strength between the first and second materials can be more improved by an existence of the intermediate layer.
In addition, it is preferable for the intermediate layer to be formed by interfusing the element comprising the second material into the first material.
In the cladding material, since the intermediate layer can be provided by interfusing the element comprising the second material into the first material, the first and second materials are metallographically continuous. Consequently, the joining strength between the first and second materials can be improved.
It is preferable for the single metal or the alloy comprising the second material to be a metal selected from the group consisting of group 4A, 5A, 6A, 7A, and 8A elements and Cu, or an alloy comprising such a metal.
Specifically, it is preferable for the single metal or the alloy comprising the second material to be a metal selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, and Cu, or an alloy comprising such a metal. In particular, it is more preferable for the single metal or the alloy comprising the second material to be a metal or an alloy which has a higher hardness and strength than those of Al or an aluminum alloy, such as Fe, an Fe alloy, Ti, Zr, Hf, Cu, a Cu alloy, Ni, and a Ni alloy. Moreover, Fe also includes so-called steel, and Fe alloys also include so-called stainless steel, such as an Fexe2x80x94Cr alloy, and an Fexe2x80x94Crxe2x80x94Ni alloy.
In addition, in order to achieve the object, the present invention provides a manufacturing method for a cladding material comprising the steps of: superposing a first material made of aluminum or an aluminum alloy and a second material made of a single metal or an alloy, and roll joining the first and second materials under vacuum conditions wherein the joining temperature is in a range from 260 to 600xc2x0 C. until the draft of the first material becomes 14% or greater.
In the manufacturing method, since the roll joining is carried out under such conditions, it is possible to realize the joining strength between the first and second materials which is larger than the tensile strength of the first material.
In the manufacturing method, it is preferable to provide an intermediate layer between the first and second materials.
In the manufacturing method, since the intermediate layer can be provided by roll joining under such conditions, it is possible to realize the joining strength between the first and second materials which is larger than the tensile strength of the first material.
In addition, it is preferable to heat treat the first and second materials under conditions wherein the heat treatment temperature is in a range from 300 to 500xc2x0 C. and the heat treatment time is in a range from 10 to 60 minutes after the roll joining.
In the manufacturing method, a crystalline phase can be formed in the intermediate layer by heat treating after the roll joining; therefore, it is possible to improve the joining strength between the first and second materials.